A 24-residue fragment of the Aβ protein; polymerizes into lattice-like structures in vitro that do not bind thioflavin T; inhibits interactions between fibrinogen and biotinylated Aβ (1-42) as well as between cholesterol and ApoE (IC50s = 13.4 and 25 μM, respectively); increases the rate of Aβ (1-40) aggregation in vitro when used at an equimolar concentration; induces cell death in cultured rat hippocampal neurons at 25 μM